Garden Resource Weed Hunter Cards Onion Weed (Allium triquetrum), also called Angled Onion Identifying characteristics This is a grass-like perennial with long, fleshy, triangular grass-like leaves that can grow to as long as 30–50 cm. It has white, bell-like flowers that grow in bunches off a triangular stem in the spring. The leaves die back every year, but the onion-like bulb will stay viable in the ground for many years. The leaves and bulb have a garlicky or onion scent; flowers. Interesting facts u All parts of this plant are edible: the white bulbs can be pickled and the green leaves can be used like chives or green onions; the flowers can be used fresh in salads. u The juice of onion weed is said to deter moths, though this is not scientifically proven. Management and removal The best organic solution is to remove onion weed by hand. Dig it up gently with a fork to get under the roots and remove the entire bulb, as pieces left in the ground will create new plants (onion weed reproduces by both division and seed). When weeding, make sure to dispose of any roots from the bulbs in the normal rubbish to avoid spreading the weed further through your composting system. This weed spreads quickly and can take some time to eradicate. Stephanie Alexander Kitchen Garden Foundation © 2013 1 Garden Resource Black Nightshade (Solanum nigrum), also called Blackberry Nightshade Identifying characteristics This bushy, herbaceous annual is found in temperate to tropical regions and can grow up to 80 cm high. The stems are green, but can turn purple as the plant ages, so you may find a mix of green and purple shades. It has long, oval-shaped, dark green leaves, with undulating edges. The flowers are white, star-shaped with five points and have yellow centres. Black nightshade berries are green at first, darkening to a very dark, almost black colour with age. Each fruit can contain up to 35 seeds. Interesting facts u Black nightshade seeds can stay dormant in the soil for more than 40 years waiting for the right conditions! u This plant has food and medicinal uses around the world, but some studies show that high levels of consumption can lead to poisoning, so it is not recommended to eat. Management and removal The plant can become invasive and can attract nematodes, viruses and fungi that can be detrimental to the soil and the plants growing it in, especially those of the Solanaceae family such as tomatoes. Remove any seedlings as soon as they appear and are identified. Hand removal is the most effective form of organic management for this weed. As flowering and seed/fruit formation begins early in summer, spring removal of the seedlings is highly recommended. The plant can be composted if it has not flowered; otherwise destroy it or add it to the regular rubbish to avoid spreading the seed further afield. Image sources: www.aphotoflora.com , en.wikipedia.org Stephanie Alexander Kitchen Garden Foundation © 2013 2 Garden Resource Oxalis (Oxalis pes-capre), also called Soursob, Soursop and Yellow-flowered Oxalis Identifying characteristics Oxalis has a clover-like, three-part, dark green leaf. It grows close to the ground and spreads quickly through a complex underground structure of bulbs. It produces small yellow flowers that tend to grow in clusters of 3–15 per stem. Management and removal Oxalis requires constant and vigilant weeding by hand, making sure to remove as many bulblets as possible from the soil. If nothing else exists in the bed or other plants can be moved or sacrificed, oxalis can be eradicated by sheet mulching with a very thick layer of cardboard or newspaper to deprive the soil – and therefore the oxalis seeds and bulbs – of light, and eventually the plants will die off. Image sources: www.dcnature.com, www.daamaaextweb.gnb.ca Stephanie Alexander Kitchen Garden Foundation © 2013 3 Garden Resource Chickweed (Stellaria media), also called Mouse-ear Chickweed Identifying characteristics Chickweed is a cool-season annual shrub with dark green, oval-shaped leaves that have pointed tips. It produces oval-shaped, hairy seed pods at the same time as its white flowers of five petals – note the notch in the petals is so deep that each petal looks like two, so the flower can appear to have ten petals. The stem has a line of fine hairs along one side only, which will change sides at each node or leaf – this one-sided hairiness is the best way to identify this genus of chickweed from others in the same family. Interesting facts u Chickweed produces flowers and sets seed at the same time rather that flowering then seeding. u The leaves, stems, flowers and seeds of chickweed are all edible and highly nutritious, with high levels of vitamins C and A as well as many minerals. u Chickweed has also been used to make ointments and salves to aid in wound healing. u The plant can also serve as a mild diuretic and is considered cleansing for the urinary tract. Management and removal If the chickweed is not in a troublesome spot in the garden, leave it and treat it as you would any other vegetable in the garden – USE IT! If you do need to remove it, be aware that it spreads by both seed and stems that root at the nodes, so when pulling up, make sure you get the whole plant. Ideally you would remove the plant before it flowers/sets seed to avoid spreading the seeds while removing it. Image sources: www.capel.verygreen.co.uk, www.cas.vanderbilt.edu Stephanie Alexander Kitchen Garden Foundation © 2013 4 Garden Resource Dandelion (Taraxacum officinale) Identifying characteristics Dandelion is biennial (two-year lifecycle), but it can be perennial in the right conditions. The leaves and stems, when cut, exude a milky white sap. The hairless leaves grow with backward-pointing teeth, flat to the ground from a single strong tap root. A single yellow flower grows on a long stem from the centre of the plant. When petals are lost, the flower head becomes a fluffy ball of seeds, from which the seeds are blown and carried by the wind. Interesting facts u Dandelion means ‘teeth of the lion’, which refers to the tooth-like petals. u Young dandelion leaves are edible raw, so are good in salads, and can also be cooked. Dandelion roots can be dried, ground up and used as a coffee substitute. u Dandelions are ‘dynamic accumulators’, which means their deep tap roots ‘mine’ nutrients from deep in the earth, storing them in their roots and leaves, so when the plant dies those nutrients are released into the top soil for the other plants to use. u Dandelions tend to prefer a higher pH level (a more ‘basic’ soil), so when present dandelions are a good indication of basic soil. Management and removal Leave dandelions if you can, in order to eat the leaves and take advantage of the benefits they bring to your soil. Organic removal of dandelions can be difficult, but if you have to remove them, there are two possible manual methods: u Cut the top off and dig around the base to loosen the taproot. Grab the root as securely as possible and give a firm tug. If the root doesn’t give, continue to dig down around the root, wiggling it to loosen it, and continue to trying to tug it out gently. The tap root can be thick, but it can also easily break, and any root left in the soil will regrow. u Cut the top off the plant and pour boiling water slowly onto its centre – this will burn and kill it. To be sure to reach all the way to the bottom of the tap root, you could remove some of the root by the previous method and follow that by pouring boiling water into the hole. Very strong vinegar (white vinegar boiled down to reduce the water content) painted or carefully sprayed on the flowers and leaves of the plant can also be somewhat effective. Image sources: wioiv.blogspot.com, www.bioinfo.org, commons.wikipedia.org Stephanie Alexander Kitchen Garden Foundation © 2013 5 Garden Resource Scotch Thistle (Onopordum acanthium); Illyrian Thistle (Onopordum Illyricum); Stemless Thistle (Onopordum acaulon); Taurian thistle (Onopordum tauricum, Victoria only) Identifying characteristics Thistles are annual or biennial plants typically found in disturbed or poor soils, often found along the roadside or on rocky hillsides. They are generally of a whitish- grey, woolly appearance, with purple flower heads emerging from a spiny/spiky casing. The stemless variety can also produce white flowers. The Scotch, Illyrian and stemless thistles all have similar colour, but the stemless remains closer to the ground while the others can get very tall. Their spiky nature makes them harmful, so wear gloves when trying to remove them. The flowering times do differ between the three main varieties: Scotch flowers through August and December, Illyrian flowers from December to February and the stemless variety flowers between October and December. Interesting facts u Globe artichokes are a member of the thistle family. u Thistle seeds can remain viable in the soil for up to eight years. u The juice of this plant has been used for centuries in medicinal ways, including curing ulcers and reducing tumours! Management and removal Unless in great numbers, thistles can be removed using a hoe or mattock to chop away the deep tap root. Monitor the area and quickly remove any regrowth that can occur from parts of the tap root left in the ground.